I read the article, and it seems to me that the pastor-turned-agnostic/atheist was trying to reconcile tradition with scripture, and simply couldn't.
He was bound in the shackles of confusion, unable to answer tough questions about evil and sin, supposed righteousness that still looks very evil, carnality in a supposedly righteous saint, worldliness in so many children of God.
I could once relate to his appetite for intellectualism, love of knowledge, his love for books and appreciation for scholarly authority. He wanted to have concrete answers for life's tough questions, and thought that men could adequately provide them.
I've read Bart Ehrman and Elaine Pagels, with their heavy appeals to the Gnosticism and all their empty rhetoric, and numerous other "scholars" with their pompous claims of authority on spiritual matters.
I'll admit that those "scholars" make some compelling arguments that appeal to intellectual pride, with the feeling that one has been enlightened above all others. But in the end, they are simply shipwrecked by empty philosophy and a prideful desire to define truth by what seems right in their own eyes
Who goes to a self professed agnostic for concrete answers? By his own admission, he has no concrete answers.
What I see in that agnostic is someone who was convinced of his Christian doctrine by men, and was not firmly grounded in truth by the Holy Spirit. Then when other men came along with seemingly better rationale, he fell headlong into the same ditch.
You should write that fellow, I think he would listen to you.